1. Field of the Invention
The present invention relates generally to a television camera and is directed more particularly to a television camera in which a so-called microcomputer is used to carry out various operations including correction of the video signal and remote control of a video tape recorder, or VTR, and in which, if the camera is used in connection with a camera control apparatus, the video signal from the camera can be easily normalized by a control signal from the control apparatus.
2. Description of the Prior Art
When, for example, the white balance of a television camera is adjusted, the television camera first picks up a white object. Then, the level of the luminance signal Y is adjusted in relation to the color difference signals (R-Y) and (B-Y) such that the levels of the color difference signals coincide with that of the video signal during the blanking period.
When one television camera is used in conjunction with one VTR, the video signal and also a control signal to control the start, stop, and other functions of the VTR are supplied from the camera to the VTR, while a control signal to command the standby and other functions of the camera is supplied from the VTR to the camera. In this case, the signal lines for these signals are gathered as a single cable and are connected together to the camera by means of a plural-pin connector.
Further, a camera control unit or CCU can be used to control a plurality of the above cameras so that the latter are selectively used to pick up an object or scene. In such case, the phases of vertical and horizontal synchronizing signals and sub-carrier signals, pedestal levels, luminance levels, chroma-levels, and various other parameters must be made coincident among the respective cameras. To this end, control signals are fed to the respective cameras from the camera control unit. The signal lines therefor are also gathered as a single cable and then connected to the cameras.
There is however an intermediate possibility between the two foregoing arrangements, namely, an arrangement in which several cameras are connected to the VTR and are connected also to the camera control unit. In this arrangement, the contents of signals transmitted therebetween are different from each other and hence the operations carried out by the cameras are also different.
In general, a conventional video camera has only one output terminal so that the camera can be connected to only one of the VTR and the CCU.
With the above arrangement, when the video signal is edited and recorded while the video signal from the camera is subjected to so-called fade-in and fade-out operations, it is conventional to adjust the level of the video signal manually and also to start and stop the tape travel of the VTR by manually operating a control switch associated with the VTR. According to such conventional techniques, however, two manual operations have to be carried out simultaneously, making the operation rather complex and making it likely that an erroneous operation may occur. Further, with such manual techniques it is impossible to assure that the times of the fade-in and fade-out operations are constant.